Behind the skillful passing and running of backup quarterback Dylan Thompson and a dominating defense led by incomparable defensive end Jadeveon Clowney, South Carolina out-gained the prolific Clemson offense by more than 100 yards en route to a sensational 27-17 victory before a sold-out crowd at Memorial Stadium on Saturday.

USC hasn't lost to Clemson since 2008, when George W. Bush was still President, and has now won four straight games over its Palmetto State rival for the first time since 1951-54.

The victory completed an impressive four-game sweep by the SEC over the ACC on Saturday as the Gamecocks were joined by Florida, Georgia and Vanderbilt in convincingly beating ACC opponents, and should propel USC back into the Top 10 of the BCS standings since the two teams in front of them (No. 10 Florida State and No. 11 Clemson) each lost to SEC schools.

"It seems like when we play Clemson, they don't play very well," USC coach Steve Spurrier said. "We did what we needed to do and made more plays than they did."

Thompson, filling in for Connor Shaw, hobbled by a sprained foot injury, out-dueled more heralded Clemson quarterback Tajh Boyd by completing 23-of-41 passes for 310 yards and three touchdowns.

After trailing 14-7 at the end of the opening 15 minutes, USC out-gained Clemson 365-165 over the final three quarters en route to its fifth win in seven games over the Tigers since 2006.

"Offensively, we did what we sort of needed to do, as far as playing sort of ugly," Spurrier said. "We ran for nothing and nothing and nothing and nothing, but we kept that clock churning away. We hit a ball or two here or there, and we got a penalty here or there. We made a lot of mistakes in the game, but fortunately, our defense was good in that second half."

USC ran 51 plays in the second half to 19 for Clemson, which totaled just 101 yards of offense in the third and fourth quarters. The Gamecocks played a masterful game of keep-away in the second half, holding the ball for 23:19.

Clemson's longest drive in the second half lasted six plays and 1:49, while the Gamecocks had time-hoarding drives of 10 (3:08), 15 (6:38) and 13 (7:39) plays.

"We couldn't get the ball in the third period. We just couldn't stop them on third down," Clemson coach Dabo Swinney said. "The third quarter was huge. We had too many penalties, too many turnovers and South Carolina did a great job of controlling the ball."

Kenny Miles and Mike Davis combined for 88 yards rushing on 28 carries, admirably filling in for the injured Marcus Lattimore.

Clowney was credited with 4.5 sacks, giving him a school-record 13 sacks for the season with one game left to be played. Along with the rest of the USC defensive line, he harassed Boyd all night and finished with seven tackles and one quarterback hurry in addition to the sack total.

"We stood him up, we moved him around a little bit, and hopefully got a one-on-one," Spurrier said. "We've got him for one more year, and we're going to shake his hand and thank him for everything he's done for South Carolina."

USC had six sacks, giving it 11 in the past two meetings with Clemson. Clowney set a Memorial Stadium record with his 4.5 sacks and 4.5 tackles for loss, breaking the opponent's record in both categories.

Clemson came into the game with one of the highest-scoring offenses in the country, but mustered just three points in the final three quarters as it was completely throttled by the USC defense after scoring two touchdowns in the first 13:38 of the game.

"I'm really, really proud of our defense," Spurrier said. "That's one of the best offenses in the country, and we held them down fairly well to 17 points."

In improving his record to 5-3 against Clemson and capturing his 65th game as coach of the Gamecocks, Spurrier became the winningest coach in USC history, passing Rex Enright (64) to ascend to the top of the all-time wins ladder.

"It seems like when we play Clemson, they don't play very well," Spurrier said.

USC has outscored Clemson 124-54 during the four-game winning streak over the hated Tigers.

Because it deferred on the coin toss, USC got the ball to start the second half trailing 14-10, and Thompson led USC on an efficient 10-play, 85-yard drive in which he completed 4-of-8 passes for 79 yards.

On third-and-16 from the Clemson 34-yard-line, Thompson got good protection, stepped up into the pocket and fired a bullet to Ace Sanders streaking over the middle. After catching the pass, Sanders side-stepped three defenders and raced into the end zone to give USC a 17-14 lead with 11:48 left, quieting the mostly pro-Clemson crowd.

Thompson led USC on an eight-play, 42-yard march on USC's second possession of the third quarter, but a pair of holding calls thwarted the Gamecocks' efforts to reach the end zone. When his scramble for a first down was negated by a holding flag, Adam Yates booted a 43-yard field goal with 6:56 left in the third quarter to increase USC's lead to 20-14.

Clemson hit a long pass on the first play of its ensuing possession, but the USC defense stiffened and the Tigers settled for a 27-yard field goal with 5:07 left in the third quarter, slicing USC's lead to 20-17.

USC mounted a drive on its third possession of the third quarter, converting a third-and-9 on a swing pass to Davis, who came on when Miles injured his knee earlier in the drive.

Eventually, USC gambled on fourth-and-11 from the 40. Thompson's pass fell harmlessly to the ground, but Clemson was flagged for pass interference, keeping the drive alive.

After another pass-interference call on the Tigers gave USC a first down, a sack by a blitzing defensive back and an interception in the left corner of the end zone left USC frustrated as it walked off the field with 13:23 left in the contest.

D.J. Swearinger's taunting penalty proved harmless when Clowney's pressure up the middle forced Boyd into a poor throw and the ball landed into the arms of safety Brison Williams in the middle of the field for his second interception of the season.

Multiple penalties on USC's ensuing possession drove the Gamecocks back, but a key third-down conversion by Thompson on third-and-19 from the Clemson 26, when he scrambled up the middle and cut right for 20 yards, led to his 6-yard touchdown pass for the final points of the game with 4:17 left.

USC converted 11-of-21 third-down opportunities.

"The quarterback draw just kept coming out, didn't it? It came out twice," Spurrier said. "Dylan made a beautiful run on one that was called back for holding. The next one, he got down to about the 5- or 6-yard line. It just worked out. Clemson's a really good team. We just made a bunch of third downs. It was probably a difference in the game."

Clemson got the ball twice in the final four minutes but did little with the opportunity. Dabo Swinney's decision to punt with 2:59 left drew loud boos from the Clemson crowd.

After the USC defense forced a three-and-out on Clemson's opening possession, a nice punt return by Sanders set up USC at the Clemson 44 for its opening series. But after reaching the Clemson 28, Thompson was sacked on third down and USC punted.

Clemson took over at the 15 and the lethal combination of a more accurate and mobile Boyd, together with some poor tackling by the Gamecocks, drove 85 yards in 16 plays for the first touchdown of the game.

Clemson converted four third-down opportunities during the drive, which drained 6:14 off the clock.

Thompson returned for the second series and completed a key third-down pass to a wide-open Justice Cunningham for a 19-yard gain to the Clemson 40. USC quickly moved into the red zone and called a timeout before Thompson fired a perfectly timed back-shoulder pass to Bruce Ellington for a 13-yard touchdown with 1:46 left in the first quarter.

The positive vibes from the touchdown drive evaporated quickly when Clemson needed all of two plays to score the go-ahead touchdown. Roderick McDowell raced around left end for 32 yards before Boyd lofted a 43-yard touchdown pass to DeAndre Hopkins, who had a half-step on USC cornerback Akeem Auguste down the left sideline.

Hopkins won the wrestling match with Auguste for possession of the ball to give Clemson a 14-7 lead with 1:22 left in the first quarter.

Thompson was 5-of-7 passing for 75 yards in the opening quarter, while Miles had 18 rushing yards on eight carries.

After the lightning-quick touchdown by the Tigers, the game settled down with each team punting twice over the next six minutes.

With 8:54 left in the second quarter, USC took possession on its own 12 and methodically drove into the Clemson red zone. Thompson scrambled for 19 yards on third-and-1 from the USC 36 for a first down to the Clemson 45, one of four rushes by the redshirt sophomore signal-caller.

Four plays later, Thompson connected with Sanders for a 17-yard pass along the sideline. The play was reviewed, then confirmed.

When the drive stalled at the Clemson 9, Yates booted a 27-yard field goal with 2:40 left until halftime, capping an impressive 12-play, 79-yard drive.

Thompson, who carried for 27 yards on the drive and completed 5-of-6 passes for 53 yards, finished the first half with 164 yards on 11-of-18 passing. He out-dueled Boyd, who completed 8-of-17 passes for 131 yards.

Miles led USC with 23 rushing yards in the opening 30 minutes. Clemson out-gained USC 237-188 in the first half, but its final three possessions ended with a pair of punts and an interception by spur DeVonte Holloman, his third career pick against Clemson.

Those stops set the tone for the dominating second half by the USC defense.